//
//  UIButton+EnlargeEdge.m
//  Answern
//
//  Created by TobyYoung on 2017/5/10.
//  Copyright © 2017年 Answern. All rights reserved.
//

#import "UIButton+EnlargeEdge.h"
#import <objc/runtime.h>

@implementation UIButton (EnlargeEdge)

static char topNameKey;
static char rightNameKey;
static char bottomNameKey;
static char leftNameKey;

- (void)setEnlargeEdge:(CGFloat) size
{
    objc_setAssociatedObject(self, &topNameKey, [NSNumber numberWithFloat:size], OBJC_ASSOCIATION_COPY_NONATOMIC);
    objc_setAssociatedObject(self, &rightNameKey, [NSNumber numberWithFloat:size], OBJC_ASSOCIATION_COPY_NONATOMIC);
    objc_setAssociatedObject(self, &bottomNameKey, [NSNumber numberWithFloat:size], OBJC_ASSOCIATION_COPY_NONATOMIC);
    objc_setAssociatedObject(self, &leftNameKey, [NSNumber numberWithFloat:size], OBJC_ASSOCIATION_COPY_NONATOMIC);
}

- (void)setEnlargeEdgeWithTop:(CGFloat) top right:(CGFloat) right bottom:(CGFloat) bottom left:(CGFloat) left
{
    objc_setAssociatedObject(self, &topNameKey, [NSNumber numberWithFloat:top], OBJC_ASSOCIATION_COPY_NONATOMIC);
    objc_setAssociatedObject(self, &rightNameKey, [NSNumber numberWithFloat:right], OBJC_ASSOCIATION_COPY_NONATOMIC);
    objc_setAssociatedObject(self, &bottomNameKey, [NSNumber numberWithFloat:bottom], OBJC_ASSOCIATION_COPY_NONATOMIC);
    objc_setAssociatedObject(self, &leftNameKey, [NSNumber numberWithFloat:left], OBJC_ASSOCIATION_COPY_NONATOMIC);
}

- (CGRect)enlargedRect
{
    NSNumber* topEdge = objc_getAssociatedObject(self, &topNameKey);
    NSNumber* rightEdge = objc_getAssociatedObject(self, &rightNameKey);
    NSNumber* bottomEdge = objc_getAssociatedObject(self, &bottomNameKey);
    NSNumber* leftEdge = objc_getAssociatedObject(self, &leftNameKey);
    if (topEdge && rightEdge && bottomEdge && leftEdge)
    {
        return CGRectMake(self.bounds.origin.x - leftEdge.floatValue,
                          self.bounds.origin.y - topEdge.floatValue,
                          self.bounds.size.width + leftEdge.floatValue + rightEdge.floatValue,
                          self.bounds.size.height + topEdge.floatValue + bottomEdge.floatValue);
    }
    else
    {
        return self.bounds;
    }
}
- (BOOL)pointInside:(CGPoint)point withEvent:(UIEvent *)event
{
    CGRect rect = [self enlargedRect];
    if (CGRectEqualToRect(rect, self.bounds))
    {
        return [super pointInside:point withEvent:event];
    }
    return CGRectContainsPoint(rect, point) ? YES : NO;
}
/*
 - (UIView*)hitTest:(CGPoint) point withEvent:(UIEvent*) event
 {
 CGRect rect = [self enlargedRect];
 if (CGRectEqualToRect(rect, self.bounds))
 {
 return [super hitTest:point withEvent:event];
 }
 return CGRectContainsPoint(rect, point) ? self : nil;
 }*/

@end



/*
 
 
 原理
 
 利用 objective-c 中的 objc_setAssociatedObject 来记录要蛮大的范围。
 
 objc_setAssociatedObject 是 objective-c runtime library 裡面的 function。
 
 需要#import <objc/runtime.h>
 
 最后，最重要的是去 override - (UIView) hitTest:(CGPoint) point withEvent:(UIEvent) event
 
 用新设定的 Rect 来当着点击范围。
 
 使用
 [enlargeButton setEnlargeEdge:20.0];
 或者[enlargeButton setEnlargeEdgeWithTop:20 right:20 bottom:20 left:10];
 
 
 */
